The Federal Aviation Administration and other international aviation regulatory agencies require commercial airlines to monitor the health and status of aircraft engines. Any health and status information is used to determine the current performance for an aircraft engine and determine if maintenance is required. Prior art techniques have been limited because of data latency and the limited amount of collected data restricted analysis. Typically, gross indicators were measured using prior art monitoring systems. Any resultant maintenance actions were reactive. For example, some prior art systems took a “snapshot” of only basic engine parameters, for example, when the aircraft had lifted to 1,000 feet after initial take-off. This data was limited to one time slot during flight and was not real time. This data never gave analysts a complete picture of an engine performance during flight. As a result, advanced prognostics and diagnostic techniques have not been used by prior art engine analysis systems.
Many jet engine original equipment manufacturers (OEMs), jet engine service providers that are contractually bound under engine maintenance cost per hour (MCPH) agreements, airline transport companies and military and commercial aviation companies have desired a system and method to monitor performance of an aircraft engine in real time and archive that data. Up to now, prior art systems were limited in their analysis to the prior art data “snapshots” and did not go beyond gross indicators and reactive maintenance techniques. In some prior art techniques, airlines have complied with regulatory requirements using several different monitoring systems. In one monitoring system, limited engine parameters (e.g., N1, N2, EGT and Wf) have been logged by pilots in aircraft log books. As noted before, automated engine data also was recorded at take-off/cruise at 1,000 feet as a “snapshot” that is recorded either “on board” or downloaded via ACARS using a VHF communication data link. This engine data resulted in a limited engine analysis because only one “snapshot” of the engine performance had been used and the “snapshot”1 never gave a true indication of engine performance during flight of the aircraft.
Harris Corporation of Melbourne, Fla. has designed a system and method of recording performance of an aircraft engine using a ground data link unit that interfaces with numerous components of the aircraft, including the DFDAU, the aircraft digital flight data recorder DFDR, and the data multiplexing system commonly referred to as the Full Authority Digital Engine Control (FADEC) for larger jet turbine engines or Engine Control Unit (ECU) as sometimes referred with smaller jet turbine engines used on smaller aircraft, including turboprops or other engines generating less than 15,000 pounds of thrust. Hereinafter, the term “FADEC/ECU” will be used corresponding to either the term “FADEC” or “ECU” as used by the industry.
An example of the Harris Corporation ground data link unit is disclosed in commonly assigned U.S. Pat. No. 6,047,165, and an engine monitoring system using the ground data link unit is disclosed in U.S. Pat. Nos. 6,148,179 and 6,353,734, the disclosures which are hereby incorporated by reference in their entirety.
In the incorporated by reference '179 and '734 patents, the system and method as disclosed can provide a record of the performance of an aircraft engine by collecting engine data during engine operation, for example, in the ground data link unit, and downloading the collected engine data over a wideband spread spectrum communications signal to a ground based spread spectrum receiver. The signal is demodulated within a ground based spread spectrum receiver to obtain the engine data for further processing. It is also possible to upload data to the ground data link unit, such as algorithms, flight management files, video and entertainment files and other data files. Although the ground data link unit as disclosed in these incorporated by reference patents is a major improvement over prior art solutions for engine monitoring, the disclosed ground data link unit is typically a large unit and interfaces with many airborne systems as described before. It would be advantageous to monitor engines in real time without resorting to the larger ground data link unit that interfaces with many systems, or by a smaller unit when the disclosed ground data link unit is not available.